T34 .48 is the best option here for drivability and reliability i would dispute the 350bhp figure quoted though more like 330bhp on your setup at 25psi.Your other option is the same turbo but a .63 housing incase you want a future upgrade as you suggested,this with suitable injectors would give you in the region of 380bhp,more than enough for a rwd Sapphire imo because you are seriously getting close to no reasonable grip.Plus any more power would need bigger brakes aswell!